Savage 308 question

5R is referring to the lands of the barrel. They are cut at an angle, which is supposed to make them clean easier and foul less. I don't think Savage does that kind of rifling, so (if I am correct) the barrel would be from another barrel maker. Either one of them should shoot fine. Savage Shooters site would be a good resource, if no one here is certain.
 
I have a Savage 10FCP 5r that I bought thru Buds Guns. It was not listed under a Savage number, I think it was a special run ordered by another company. The barrel may well have been made by another barrel maker, I do know it will shoot better than I can at present.